U.S. patent application number 16/771606 was filed with the patent office on 2020-09-24 for battery pack.
The applicant listed for this patent is Samsung SDI Co., Ltd.. Invention is credited to Soomin AHN, Eungyeong GU, Youngdeok KIM, Sora LEE, Minkyun MOK, Janghyun SONG.
Application Number | 20200303701 16/771606 |
Document ID | / |
Family ID | 1000004905488 |
Filed Date | 2020-09-24 |
United States Patent
Application |
20200303701 |
Kind Code |
A1 |
KIM; Youngdeok ; et
al. |
September 24, 2020 |
BATTERY PACK
Abstract
Provided is a battery pack. The battery pack includes: a battery
cell including a cell vent; frames arranged together with the
battery cell in a direction and coupled together to face each other
with the battery cell therebetween, the frames including guide ribs
surrounding the cell vent; and a top cover arranged above the
frames to cover the frames and including a protruding barrier wall
surrounding the guide ribs. According to the present disclosure,
the battery pack has an improved vent structure to rapidly
discharge gas generated in an abnormal battery cell to the outside
of the battery pack.
Inventors: |
KIM; Youngdeok; (Yongin-si,
KR) ; LEE; Sora; (Yongin-si, KR) ; GU;
Eungyeong; (Yongin-si, KR) ; MOK; Minkyun;
(Yongin-si, KR) ; SONG; Janghyun; (Yongin-si,
KR) ; AHN; Soomin; (Yongin-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung SDI Co., Ltd. |
Yongin-si, Gyeonggi-do |
|
KR |
|
|
Family ID: |
1000004905488 |
Appl. No.: |
16/771606 |
Filed: |
November 16, 2018 |
PCT Filed: |
November 16, 2018 |
PCT NO: |
PCT/KR2018/014124 |
371 Date: |
June 10, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 2/1235 20130101;
H01M 2/1077 20130101 |
International
Class: |
H01M 2/12 20060101
H01M002/12; H01M 2/10 20060101 H01M002/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2017 |
KR |
10-2017-0169536 |
Claims
1. A battery pack comprising: a battery cell comprising a cell
vent; frames arranged together with the battery cell in a direction
and coupled together to face each other with the battery cell
therebetween, the frames comprising guide ribs surrounding the cell
vent; and a top cover arranged above the frames to cover the frames
and comprising a protruding barrier wall surrounding the guide
ribs.
2. The battery pack of claim 1, wherein the guide ribs form a
discharge hole at a position corresponding to the cell vent.
3. The battery pack of claim 2, wherein the guide ribs surround the
discharge hole.
4. The battery pack of claim 1, wherein the guide ribs have an
elliptical shape corresponding to the cell vent.
5. The battery pack of claim 1, wherein, as the frames arranged in
the direction at front and rear sides of the battery cell with the
battery cell therebetween are coupled to each other, the guide ribs
entirely surround the cell vent of the battery cell.
6. The battery pack of claim 1, wherein the battery cell comprises
a plurality of battery cells arranged in the direction, and a
plurality of guide ribs surround the cell vent of each of the
battery cells as frames arranged in the direction with the battery
cells therebetween are coupled to each other.
7. The battery pack of claim 1, wherein the guide ribs and the
protruding barrier wall protrude in mutually-facing directions from
main bodies of the frames and a main body of the top cover.
8. The battery pack of claim 7, wherein the guide ribs and the
protruding barrier wall form a tunnel-type discharge path.
9. The battery pack of claim 7, wherein leading ends of the guide
ribs in the protruding direction of the guide ribs are spaced
apart, by a clearance gap, from a leading end of the protruding
barrier wall in the protruding direction of the protruding barrier
wall.
10. The battery pack of claim 9, wherein the leading ends of the
guide ribs are at inner positions relatively close to a center
position of the cell vent, and the leading end of the protruding
barrier wall is at an outer position relatively distant from the
center position of the cell vent.
11. The battery pack of claim 10, wherein, when the battery cell
swells, the guide ribs provided as a pair surrounding the cell vent
of the battery cell are moved outward away from each other.
12. The battery pack of claim 1, wherein the guide ribs protrude
from main bodies of the frames toward the top cover and are
inclined to converge with a width gradually decreasing in a
protruding direction of the guide ribs.
13. The battery pack of claim 12, wherein the guide ribs are
inclined to have a cross-section gradually decreasing in the
protruding direction of the guide ribs.
14. The battery pack of claim 1, wherein the protruding barrier
wall protrudes from a main body of the top cover toward the frames
in a parallel form to have a width which is substantially uniform
in a protruding direction of the protruding barrier wall.
15. The battery pack of claim 1, wherein a wiring board is arranged
between the top cover and the frames F, and a through-hole is
formed in the wiring board to receive the guide ribs or the
protruding barrier wall.
16. The battery pack of claim 15, wherein the protruding barrier
wall or the guide ribs are inserted through the through-hole such
that the protruding barrier wall or the guide ribs completely
penetrate the wiring board.
17. The battery pack of claim 1, wherein a module vent is formed on
the top cover at a position corresponding to the cell vent.
18. The battery pack of claim 17, wherein the module vent comprises
a break line formed by recessing a portion of an upper or lower
surface of the top cover in a thickness direction of the top
cover.
19. The battery pack of claim 18, wherein the break line comprises:
a border line formed in a closed loop along a border of the module
vent; and a center line formed to cross the border line.
20. The battery pack of claim 19, wherein hinge portions are formed
on both lateral portions of the border line which face the center
line.
21. The battery pack of claim 20, wherein the hinge portions have a
thickness greater than a thickness of the center line.
22. The battery pack of claim 20, wherein the module vent is opened
toward both sides of the center line while being broken along the
center line and folded at the hinge portions.
23. The battery pack of claim 19, wherein the center line extends
in a direction crossing the module vent at a center position of the
module vent.
24. The battery pack of claim 17, wherein the battery cell
comprises a plurality of battery cells arranged in the direction,
and the module vent comprises a plurality of module vents
respectively corresponding to the cell vents of the plurality of
battery cells.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a battery pack.
BACKGROUND ART
[0002] In general, secondary batteries refer to batteries that can
be repeatedly charged and recharged unlike non-rechargeable primary
batteries. Secondary batteries are used as energy sources of
devices such as mobile devices, electric vehicles, hybrid electric
vehicles, electric bicycles, and uninterruptible power supplies.
Single-cell secondary batteries or multi-cell secondary batteries
(battery packs) each including a plurality of cells connected to
each other are used according to the types of devices that employ
secondary batteries.
[0003] Small mobile devices such as cellular phones may be operated
for a predetermined time using single-cell secondary batteries.
However, battery packs having high-output, high-capacity features
may be suitable for devices having long operating times and
consuming large amounts of power such as electric vehicles and
hybrid electric vehicles. The output voltages or currents of
battery packs may be increased by adjusting the number of battery
cells included in the battery packs.
DESCRIPTION OF EMBODIMENTS
Technical Problem
[0004] An embodiment of the present disclosure includes a battery
pack having an improved vent structure to rapidly discharge gas
generated in an abnormal battery cell to the outside of the battery
pack.
Solution to Problem
[0005] A battery pack includes:
[0006] a battery cell including a cell vent;
[0007] frames arranged together with the battery cell in a
direction and coupled together to face each other with the battery
cell therebetween, the frames including guide ribs surrounding the
cell vent; and
[0008] a top cover arranged above the frames to cover the frames
and including a protruding barrier wall surrounding the guide
ribs.
Advantageous Effects of Disclosure
[0009] According to the present disclosure, short discharge paths
are fluidly connected to the cell vents of battery cells, thereby
making it possible to rapidly discharge gas ejected from the cell
vents through the short discharge paths, prevent other normal
battery cells or circuit devices mounted on a wiring board from be
negatively affected by high-temperature gas flowing along a
discharge path, and interrupt thermal runway consecutively
propagating from an abnormal battery cell to normal battery
cells.
[0010] According to the present disclosure, tunnel-type discharge
paths are connected to the cell vents of battery cells, thereby
preventing leakage of high-temperature gas to other battery cells
or circuit devices of a wiring board through a discharge path.
[0011] According to the present disclosure, a plurality of module
vents are provided in fluid connection with the cell vents of
battery cells such that gas may be rapidly discharged from the cell
vent of an abnormal battery cell through the shortest discharge
path regardless of the position of the abnormal battery cell, and
safety accidents such as explosions caused by a delay of gas
discharge may be prevented.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is an exploded perspective view illustrating a
battery pack according to an embodiment of the present
disclosure.
[0013] FIG. 2 is an exploded perspective view illustrating a
portion of the battery pack shown in FIG. 1.
[0014] FIG. 3 is a plan view illustrating a portion of the battery
pack shown in FIG. 1.
[0015] FIG. 4 is an exploded perspective view illustrating a
portion of the battery pack shown in FIG. 1.
[0016] FIG. 5 is a cross-sectional view taken along line V-V of
FIG. 4.
[0017] FIG. 6 is another exploded perspective view illustrating the
battery pack shown in FIG. 1.
[0018] FIG. 7 is a view illustrating a module vent shown in FIG.
6.
[0019] FIG. 8 is a cross-sectional view taken along line VIII-VIII
of FIG. 7.
[0020] FIG. 9 is a view illustrating a modification of the guide
ribs shown in FIG. 5, according to another embodiment.
BEST MODE
[0021] A battery pack includes:
[0022] a battery cell including a cell vent;
[0023] frames arranged together with the battery cell in a
direction and coupled together to face each other with the battery
cell therebetween, the frames including guide ribs surrounding the
cell vent; and
[0024] a top cover arranged above the frames to cover the frames
and including a protruding barrier wall surrounding the guide
ribs.
[0025] For example, the guide ribs may form a discharge hole at a
position corresponding to the cell vent.
[0026] For example, the guide ribs may surround the discharge
hole.
[0027] For example, the guide ribs may have an elliptical shape
corresponding to the cell vent.
[0028] For example, as the frames arranged in the direction at
front and rear sides of the battery cell with the battery cell
therebetween are coupled to each other, the guide ribs may entirely
surround the cell vent of the battery cell.
[0029] For example, the battery cell may include a plurality of
battery cells arranged in the direction, and
[0030] a plurality of guide ribs may surround the cell vent of each
of the battery cells as frames arranged in the direction with the
battery cells therebetween are coupled to each other.
[0031] For example, the guide ribs and the protruding barrier wall
may protrude in mutually-facing directions from main bodies of the
frames and a main body of the top cover.
[0032] For example, the guide ribs and the protruding barrier wall
form a tunnel-type discharge path.
[0033] For example, leading ends of the guide ribs in the
protruding direction of the guide ribs may be spaced apart, by a
clearance gap, from a leading end of the protruding barrier wall in
the protruding direction of the protruding barrier wall.
[0034] For example, the leading ends of the guide ribs may be at
inner positions relatively close to a center position of the cell
vent, and the leading end of the protruding barrier wall may be at
an outer position relatively distant from the center position of
the cell vent.
[0035] For example, when the battery cell swells, the guide ribs
provided as a pair surrounding the cell vent of the battery cell
may be moved outward away from each other.
[0036] For example, the guide ribs may protrude from main bodies of
the frames toward the top cover and may be inclined to converge
with a width gradually decreasing in a protruding direction of the
guide ribs.
[0037] For example, the guide ribs may be inclined to have a
cross-section gradually decreasing in the protruding direction of
the guide ribs.
[0038] For example, the protruding barrier wall may protrude from a
main body of the top cover toward the frames in a parallel form to
have a width which is substantially uniform in a protruding
direction of the protruding barrier wall.
[0039] For example, a wiring board may be arranged between the top
cover and the frames F, and
[0040] a through-hole may be formed in the wiring board to receive
the guide ribs or the protruding barrier wall.
[0041] For example, the protruding barrier wall or the guide ribs
may be inserted through the through-hole such that the protruding
barrier wall or the guide ribs may completely penetrate the wiring
board.
[0042] For example, a module vent may be formed on the top cover at
a position corresponding to the cell vent.
[0043] For example, the module vent may include a break line formed
by recessing a portion of an upper or lower surface of the top
cover in a thickness direction of the top cover.
[0044] For example, the break line may include:
[0045] a border line formed in a closed loop along a border of the
module vent; and
[0046] a center line formed to cross the border line.
[0047] For example, hinge portions may be formed on both lateral
portions of the border line which face the center line.
[0048] For example, the hinge portions may have a thickness greater
than a thickness of the center line.
[0049] For example, the module vent may be opened toward both sides
of the center line while being broken along the center line and
folded at the hinge portions.
[0050] For example, the center line may extend in a direction
crossing the module vent at a center position of the module
vent.
[0051] For example, the battery cell may include a plurality of
battery cells arranged in the direction, and
[0052] the module vent may include a plurality of module vents
respectively corresponding to the cell vents of the plurality of
battery cells.
MODE OF DISCLOSURE
[0053] Battery packs will now be described with reference to the
accompanying drawings, in which preferable embodiments are
shown.
[0054] FIG. 1 is an exploded perspective view illustrating a
battery pack according to an embodiment of the present disclosure.
FIG. 2 is an exploded perspective view illustrating a portion of
the battery pack illustrated in FIG. 1. FIG. 3 is a plan view
illustrating a portion of the battery pack illustrated in FIG.
1.
[0055] Referring to the drawings, the battery pack of the present
disclosure includes: battery cells B including cell vents V; frames
F arranged together with the battery cells B in a direction
(hereinafter, also referred to as a direction Z1) and are coupled
to each other to face each other with the battery cells 10
therebetween; and a top cover TC provided above the frames F to
cover the frames F. In addition, the frames F may include guide
ribs GR surrounding cell vents V of the battery cells B, and the
top cover TC may include module vents MV formed at positions
corresponding to the cell vents V.
[0056] The battery cells B may be arranged in a direction
(direction Z1). In addition, the frames F may be arranged together
with the battery cells B in the direction (direction Z1) in such a
manner that the frames F are coupled to each other with the battery
cells B therebetween. The frames F may be arranged in the direction
(direction Z1) in such a manner that a battery cell B is placed
between every neighboring frames F, and the neighboring frames F
are coupled to each other while facing each other.
[0057] Each of the frames F may define an accommodation portion FA
surrounding the periphery of a battery cell B and extending along
the periphery of the battery cell B to accommodate the battery cell
B. More specifically, the frame F may extend along the periphery of
the battery cell B while crossing upper, lower, and lateral sides
of the battery cell B. The frame F may include: the accommodation
portion FA as an inner region accommodating the battery cell B: and
a support portion FS as an outer region on which objects making
electrical connection with the battery cell B such as bus bars 15
and the wiring board C are supported. For example, the support
portion FS may be formed on a portion of the frame F which crosses
the upper side of the battery cell B on which electrodes 10 are
formed. The frame F may have an inner side surrounding the battery
cell B and an outer side forming the support portion FS, thereby
providing a support base for objects making electrical connection
with the battery cell B such as the bus bars 15 and the wiring
board C.
[0058] The frames F may be arranged in the direction (hereinafter,
also referred to as the direction Z1) in such a manner that a
battery cell B is placed between every neighboring frames F, and
the neighboring frames F are coupled to each other while facing
each other. In other words, all the battery cells B are surrounded
by the frames F arranged forward and backward in the direction
(direction Z1), and the frames F, which are arranged forward and
backward, surround the outsides of the battery cells B placed
between the frames F such that the frames F may form the exterior
of the battery pack covering the battery cells B and may function
as a housing protecting the battery cells B. In the battery pack
including the battery cells B, the array of the frames F in the
direction (direction Z1) may substantially form the exterior of the
battery pack, and the battery cells B may be placed inside the
array of the frames F and surrounded by the frames F.
[0059] The frames F and the battery cells B may be alternately
arranged in the direction (direction Z1), and each of the frames F
may include different accommodation portions FA accommodating
neighboring battery cells B. For example, each of the frames F may
include different accommodation portions FA that accommodate
different battery cells B arranged forward and backward in the
direction (direction Z1), and the different accommodation portions
FA may be separated from each other by a barrier wall W. In the
frame F, the barrier wall W may be placed between the different
accommodation portions FA to separate the accommodation portions FA
from each other and may block electrical and thermal interference
between the different battery cells B.
[0060] Each of the battery cells B may be connected to bus bars 15
for electrical connection with neighboring battery cells B, and the
wiring board C may be connected to the battery cells B to obtain
state information such as voltage or temperature information about
the battery cells B. In this case, the bus bars 15 and the wiring
board C may be objects forming electrical connection with the
battery cells B, and such objects may be supported on the support
portions FS of the frames F.
[0061] The support portions FS of the frames F may include bus bar
support portions FSB on which bus bars 15 are supported, and board
support portions FSC on which the wiring board C is supported. The
bus bar support portions FSB and the board support portions FSC may
be provided on different positions of the support portions FS. For
example, the bus bar support portions FSB may be provided on left
or right peripheral portions of the frames F corresponding to the
electrodes 10 of the battery cells B. The board support portions
FSC may be provided on center portions of the frames F. The wiring
board C supported on the board support portions FSC may be at
center positions of the battery cells B such that the wiring board
C may easily collect state information from a plurality of
positions of the battery cells B. Sensing portions S may be
connected to the wiring board C to transmit state information from
sides of the battery cells B, and since the wiring board C is
placed at a center position, the distances between the wiring board
C and the sensing portions S connected to the plurality of
positions from the wiring board C may be substantially uniform and
may be balanced such that the electrical resistances of the sensing
portions S connected to the plurality of positions may be balanced
to prevent signal distortion.
[0062] The bus bar support portions FSB and the board support
portions FSC may have different widths. For example, the bus bar
support portions FSB may be relatively narrow in order not to
interfere electrical connection between the bus bars 15 and the
battery cells B (specifically, the electrodes 10 of the battery
cells B). The bus bar support portions FSB may support front and
back end portions of the bus bars 15 which are placed on both sides
of bent portions 15a of the bus bars 15 and may insulate
neighboring bus bars 15 from each other. The bus bar support
portions FSB may support both end portions of the bus bars 15 and
may electrically insulate neighboring bus bars 15 from each other
such that both end portions of a bus bar 15 may not make contact
with end portions of neighboring bus bars 15. The bus bar support
portions FSB do not need to make physical contact with both end
portions of the bus bars 15 as long as the bus bar support portions
FSB are placed between neighboring bus bars 15 and electrically
insulate the neighboring bus bars 15 from each other. Since it is
sufficient that the bus bar support portions FSB are placed between
the bus bars 15 neighboring each other to prevent electrical
contact between the bus bars 15, the bus bar support portions FSB
may have a relatively small width so as not to decrease the
conduction area between the bus bars 15 and the electrodes 10 of
the battery cells B. When the bus bar support portions FSB have a
large width like the board support portions FSC, electrical contact
between the bus bars 15 and the battery cells B (specifically, the
electrodes 10 of the battery cells B) may be hindered, and the
conduction area between the bus bars 15 and the battery cells B may
be decreased, increasing the electrical resistance of an overall
charge-discharge path and decreasing the electrical output power of
the battery pack.
[0063] The board support portions FSC have a relatively large width
such that the wiring board C may be stably placed and supported on
the board support portions FSC. The wiring board C may be placed on
the board support portion FSC of each of the frames F, and the
board support portions FSC of the frames F may be connected to each
other in the direction (direction Z1) to form a support surface
widely extending in the direction (direction Z1), thereby providing
a support base for supporting the wiring board C. That is, while
the board support portions FSC of the frames F support the wiring
board C, the board support portions FSC of the frames F may be
connected to each other in the direction (direction Z1) to form a
support surface widely extending in the direction (direction Z1),
and thus a support base for stably supporting the wiring board C
may be provided.
[0064] The bus bars 15 are for electrically connecting the battery
cells B neighboring each other, and the bus bars 15 may connect the
battery cells B in series, parallel, or series-parallel to each
other. The bus bars 15 may electrically connect the neighboring
battery cells B to each other by electrically coupling the
electrodes 10 of the battery cells B. Specifically, the bus bars 15
may connect the neighboring battery cells B in parallel to each
other by connecting electrodes 10 of the battery cells B having the
same polarity or in series to each other by connecting electrodes
10 of the battery cells B having different polarities.
[0065] The bus bars 15 may be arranged to face the electrodes 10
provided on upper surfaces of the neighboring battery cells B and
may electrically connect the electrodes 10 of the neighboring
battery cells B to each other. More specifically, based on the bent
portions 15a provided at center positions of the bus bars 15, both
sides of the bus bars 15 may be pointed toward and coupled to the
electrodes 10 of the battery cells B. A plurality of bus bars 15
may connect electrodes 10 of a pair of neighboring battery cells
B.
[0066] The board support portions FSC may be placed at center
positions between the bus bar support portions FSB provided at left
and right peripheral portions. The wiring board C may be placed on
the board support portions FSC. The wiring board C may include a
plurality of conductive patterns (not shown) to collect state
information about the battery cells B and transmit the state
information to a battery managing unit (not shown). The wiring
board C may be electrically connected to the battery cells B, and
for example, the wiring board C may be connected to the bus bars 15
used to electrically couple the battery cells B to each other and
obtain information about the voltages of the battery cells B.
Although not shown in the drawings, the wiring board C may be
connected to thermistors (not shown) placed on the upper surfaces
of the battery cells B to obtain information about the temperatures
of the battery cells B.
[0067] The wiring board C may collect state information, for
example, voltage and temperature information, from the battery
cells B and may transmit the state information to a separate
battery managing unit (not shown) such that the separate battery
managing unit (not shown) may control charge-discharge operations
of the battery cells B, or the charge-discharge operations of the
battery cells B may be controlled by a battery managing unit
provided together with the wiring board C.
[0068] Referring to FIG. 3, the sensing portions S which are
flexible may be connected to the wiring board C to as media for
transmitting signals relating to battery cell state information.
The sensing portions S may be provided in the form of a flexibly
deformable film. Although not shown in the drawings, each of the
sensing portions S may include an insulative film (not shown) and a
conductive line (not shown) provided on the insulative film. For
example, the conductive line (not shown) may be a copper foil
pattern, and the insulative film (not shown) may be arranged to
bury the conductive line (not shown) in the insulative film (not
shown) such that electrical signals transmitted through the
conductive line (not shown) may be insulated from the outside.
[0069] Each of the sensing portions S may include an input port SI
connected to a side of a battery cell B, an output port SO
connected to the wiring board C, and a connection portion SC
connecting the input port SI and the output port SO to each other.
For example, the input port SI may correspond to a portion
receiving state information from the side of the battery cell B,
and the output port SO may correspond to a portion through which
the state information about the battery cell B is output to the
wiring board C.
[0070] More specifically, the input ports SI of the sensing
portions S may be connected to sides of the battery cells B. The
input ports SI of the sensing portions S may be connected to the
bus bars 15 electrically connecting the battery cells B neighboring
each other and may receive voltage signals of the battery cells B
through the bus bars 15. Although not shown in the drawings,
according to another embodiment of the present disclosure, the
input ports SI may be connected to the thermistors (not shown)
placed on the upper surfaces of the battery cells B and may receive
temperature signals of the battery cells B from the thermistors
(not shown). In this view, the input ports SI of the sensing
portions S may be considered as being connected to signal input
portions for acquiring state information about the battery cells B.
The signal input portions may be connected to the battery cells B
for acquiring state information such as the voltages or
temperatures of the battery cells B and may be, for example, the
bus bars 15 electrically connected to the battery cells B or the
thermistors (not shown) thermally connected to the battery cells B.
The input ports SI may be welded to the signal input portions (for
example, the bus bars 15) provided on the sides of the battery
cells B. For example, the input ports SI may be welded to the bus
bars 15 using ultrasonic waves by placing the input ports SI on the
bus bars 15 and then pressing the input ports SI with an ultrasonic
horn (not shown) applying ultrasonic vibration thereto. In another
embodiment of the present disclosure, the input ports SI and the
signal input portions (for example, the bus bars 15) provided on
the sides of the battery cells B may be coupled to each other using
a conductive adhesive or the like.
[0071] The output ports SO of the sensing portions S may be
connected to pads (not shown) of the wiring board C, and electrical
signals transmitted through the output ports SO of the sensing
portions S may arrive at the conductive patterns (not shown) of the
wiring board C via the pads (not shown) of the wiring board C. The
output ports SO of the sensing portions S may be welded or soldered
to the pads (not shown) of the wiring board C or may be coupled to
the pads of the wiring board C using a conductive adhesive or the
like.
[0072] Each of the connection portions SC, which connects the input
port SI and the output port SO to each other, may be formed in a
curved shape in which curved portions overlap each other. The
battery pack may include the frames F facing each other and coupled
to each other with the battery cells B therebetween in the
direction (direction Z1) in which the battery cells B are arranged.
During the charge-discharge operations of the battery cells B, the
battery cells B may undergo swelling, that is, expansion, in the
direction (direction Z1), and in this case, the frames F which are
forwardly and backwardly coupled to each other with the battery
cells B therebetween in the direction (direction Z1), may slide in
the direction (direction Z1) and accommodate deformation caused by
the swelling of the battery cell B.
[0073] As described above, when the battery cells B swell and
expand in the direction (hereinafter, also referred to as the
direction Z1), the frames F may move in the direction (direction
Z1), and thus the relative positions of the input ports SI coupled
to the bus bars 15 placed on the frames F and the output ports SO
coupled to the wiring board C may become farther from each other in
the direction (direction Z1). In this case, the connection portions
SC connecting the input ports SI and the output ports SO may deform
to accommodate the deformation in the direction (direction Z1). In
this case, since the connection portions SC have a curved shape in
which curved portions overlap each other, the connection portions
SC may be easily deformed according to the relative positions of
the input ports SI and the output ports SO which are moved away
from each other because of the swelling, and thus less stress may
be accumulated in the connection portions SC.
[0074] In FIG. 1, reference numerals E and 210 refer to end blocks
and end plates, respectively. The end blocks E and the end plates
210 may be placed on the outer sides of the outermost battery cells
B to provide fastening force for physically restraining the battery
cells B of the battery pack.
[0075] FIG. 4 is an exploded perspective view illustrating a
portion of the battery pack illustrated in FIG. 1. FIG. 5 is a
cross-sectional view taken along line V-V of FIG. 4.
[0076] Referring to the drawings, the battery pack of the present
disclosure includes: the battery cells B including the cell vents
V; and the frames F arranged together with the battery cells B in
the direction (direction Z1) and are coupled to each other to face
each other with the battery cells 10 therebetween, wherein the
frames F may include guide ribs GR formed to surround the cell
vents V.
[0077] More specifically, the guide ribs GR may be provided on the
frames F to form discharge holes FV at positions corresponding to
the cell vents V of the battery cells B. For example, the guide
ribs GR may be formed on the frames F which cross the upper sides
of the battery cells B in which the cell vents V are formed. For
example, the guide ribs GR may be formed on the support portions FS
(specifically, the board support portions FSC) of the frames F that
cross the upper sides of the battery cells B, and the guide ribs GR
may be at positions corresponding to the cell vents V of the
battery cells B.
[0078] The discharge holes FV may be formed at positions
corresponding to the cell vents V of the battery cells B, and the
guide ribs GR may form the discharge holes FV while being arranged
along the peripheries of the discharge holes FV to surround the
discharge holes FV. The guide ribs GR may be fluidly connected to
the cell vents V of the battery cells B to provide discharge paths
for gas discharged through the cell vents V, and may thus be formed
at positions corresponding to the cell vents V and have a shape
corresponding to the shape of the cell vents V. For example, the
guide ribs GR may be formed in an elliptical shape corresponding to
the cell vents V, and the discharge holes FV formed by the guide
ribs GR may also have an elliptical shape corresponding to the cell
vents V.
[0079] The guide ribs GR may formed at positions corresponding to
the cell vents V of the battery cells B and may protrude in a
direction opposite the cell vents V. The guide ribs GR may protrude
opposite the cell vents V in a gas discharge direction to form the
discharge paths for gas discharged through the cell vents V. For
example, the guide ribs GR may protrude from main bodies (or the
support portions FS) of the frames F in a direction opposite the
cell vents V.
[0080] The guide ribs GR may surround the cell vents V of the
battery cells B. Here, since the frames F are at upper positions of
the battery cells B, it can be understood that the guide ribs GR
formed on the frames F surround upper sides of the cell vents V of
the battery cells B rather than directly surrounding the cell vents
V of the battery cells B. For example, the guide ribs GR may
surround the discharge holes FV formed above the cell vents V.
[0081] The expression "the guide ribs GR are formed to surround the
cell vents V of the battery cells B" refers to the case in which a
guide rib GR formed on each of the frames F surrounds a portion of
a cell vent V as well as the in the case in which a guide rib GR
formed on each of the frames F entirely surrounds a cell vent V.
For example, each of the guide ribs GR may be formed in an open
shape to surround a portion of a cell vent, a pair of guide ribs GR
provided on front and rear frames F coupled together to face each
other with a battery cell B therebetween may be coupled to each
other to entirely surround the cell vent V of the battery cell B,
and thus a discharge hole FV having an elliptical shape
corresponding to the cell vent V of the battery cell B may be
provided by the pair of guide ribs GR.
[0082] Similarly, the expression "the guide ribs GR and the
discharge holes FV are formed in an elliptical shape corresponding
to the cell vents of the battery cells B" may refer to the case in
which a guide rib GR and a discharge hole FV formed on each of the
frames F is shaped like a portion of an ellipse as well as the case
in which a guide rib GR and a discharge hole FV formed on each of
the frames F has a complete elliptical shape. For example, each of
the guide ribs GR and each of the discharge holes FV may be formed
in a shape having an open side, and as a pair of guide ribs GR
provided on front and rear frames F coupled together to face each
other with a battery cell B therebetween are coupled to each other,
the pair of guide ribs GR may have an complete elliptical shape,
and a discharge hole FV having an complete elliptical shape may be
provided.
[0083] The frames F and the battery cells B may be alternately
arranged in the direction (direction Z1), and each of the frames F
may include different accommodation portions FA to accommodate
neighboring battery cells B. In addition, the guide ribs GR
protruding from the main bodies of the frames F, and the discharge
holes FV formed by the guide ribs GR may correspond to the cell
vents V of the battery cells B neighboring each other and may be
provided as pairs above the cell vents V of the battery cells B. In
this case, the guide ribs GR protruding from the main bodies of the
frames F, and the discharge holes FV formed by the guide ribs GR
may be at positions corresponding to the cell vents V which are
separated by the partition walls W each separating the
accommodation portions FA of a frame from each other.
[0084] Referring to FIG. 5, the guide ribs GR may be formed in a
shape having a relatively wide lower side and a relatively narrow
upper side in a vertical direction along the discharge paths. That
is, the guide ribs GR are inclined in a converging manner to have a
cross-sectional shape gradually decreasing in an upward direction
from the discharge holes FV, such that the flows of gas guided by
the guide ribs GR may converge at center positions of the guide
ribs GR and the pressure of gas may be concentrated at the center
positions of the guide ribs GR. Since the cross sections of the
guide ribs GR refer to cross-sectional areas through which gas
passes, the gradually decreasing cross-sectional shape of the guide
ribs GR may increase the pressure of gas and concentrate the flows
of gas at the center positions of the guide ribs GR.
[0085] The guide ribs GR may protrude in a direction opposite the
battery cells B from the support portions FS of the frames F that
cross the upper sides of the battery cells B in which the cell
vents V are formed, and may make a constant oblique angle .theta.
with the support portions FS of the frames F. More specifically,
the oblique angle .theta. of the guide ribs GR may be greater than
90 degrees with respect to the support portions FS of the frames F
such that the cross-sectional shape of the guide ribs GR may be
gradually tapered in an upward direction. That is, the oblique
angle .theta. of the guide ribs GR from the support portions FS of
the frames F may be set to be within the range of 90
degrees<.theta.<180 degrees. The oblique angle .theta. of the
guide ribs GR may be set such that the guide ribs GR may have a
left-right symmetrical structure and may converge toward the center
positions of the guide ribs GR. For example, the guide ribs GR may
surround the discharge holes FV, have an elliptical shape like the
discharge holes FV, and protrude in a direction opposite the
battery cells B.
[0086] Each pair of the guide ribs GR may be formed by coupling a
pair of frames F arranged back and forth with a battery cell B
therebetween in the direction (direction Z1). For example, front
and rear frames F may be coupled together to face each other with a
battery cell B therebetween such that a guide rib GR of the front
frame F and a guide rib GR of the rear frame F may be coupled to
each other at a position corresponding to the cell vent V of the
battery cell B to entirely surround the cell vent V of the battery
cell B. The frames F may be arranged in the direction (direction
Z1) and may be coupled together with the battery cells B
therebetween such that pairs of the guide ribs GR may be provided
at positions corresponding to the cell vents V of the battery cells
B to surround the cell vents V. The guide ribs GR may be formed to
surround the cell vents V of the battery cells B and may provide
the discharge paths for gas discharged through the cell vents V.
The gas discharged through the cell vents V may flow through the
discharge holes FV and may then be discharged through the top cover
TC provided above the discharge holes FV while being guided by the
guide ribs GR.
[0087] Like the guide ribs GR, each pair of discharge holes FV may
be formed by coupling a pair of frames F arranged back and forth
with a battery cell B therebetween in the direction (direction Z1).
For example, front and rear frames F may be coupled together to
face each other with a battery cell B therebetween such that a
discharge hole FV of the front frame F and a discharge hole FV of
the rear frame F may be coupled to each other at a position
corresponding to the cell vent V of the battery cell B to form a
complete elliptical shape. That is, the frames F may be arranged in
the direction (direction Z1) and may be coupled together with the
battery cells B therebetween such that the discharge holes FV may
be provided at positions corresponding to the cell vents V of the
battery cells B and the guide ribs GR surrounding the discharge
holes FV may be provided.
[0088] The guide ribs GR and the discharge holes FV may be formed
at positions corresponding to the cell vents V of the battery cells
B. The guide ribs GR and the discharge holes FV may be provided at
positions corresponding to the cell vents V of the battery cells B
as the frames arranged on the front and rear sides of the battery
cells B in the direction (direction Z1) are coupled to each other.
For example, as a pair of frames F arranged on the front and rear
sides of a battery cell B are coupled to each other, a guide rib GR
and a discharge hole FV of the front frame F may be coupled to a
guide rib GR and a discharge hole FV of the rear frame F such that
the guide ribs GR and the discharge holes FV may be provided at a
position corresponding to the cell vent V of the battery cell B to
entirely surround the cell vent V of the battery cell B.
[0089] The guide ribs GR and the discharge holes FV may be formed
at positions corresponding to the cell vents V of the battery cells
B. That is, the guide ribs GR and the discharge holes FV may be
formed at positions corresponding to the cell vents V of the
battery cells B along the arrangement of the frames F connected to
each other with the battery cells B therebetween.
[0090] When one of the battery cells B is locally overheated and
the cell vent V of the battery cell B is operated, gas is
discharged through the cell vent V and is guided to the top cover
TC along guide ribs GR surrounding the cell vent V while not
leaking to other battery cells B owing to the guide ribs GR. When
high-temperature gas discharged from one of the battery cells B
flows to adjacent battery cells B, thermal runway may consecutively
occur at the adjacent battery cells B, and to prevent this, the
guide ribs GR define the discharge paths such that gas discharged
from one of the battery cells B does not flow to other battery
cells B.
[0091] In the present disclosure, since the discharge holes FV and
the guide ribs GR are formed corresponding to the cell vents V of
the battery cells B, gas discharged from one of the battery cells B
may not flow to other battery cells B but may be discharged to the
outside of the battery pack through a short discharge path. That
is, in the present disclosure, the discharge paths are not formed
in the direction (hereinafter, also referred as the direction Z1)
in which the battery cells B are arranged, but are formed as short
paths in a vertical direction perpendicular to the direction
(direction Z1). In a comparative example for comparison with the
present disclosure, gas discharged from one of the battery cells B
is discharged to the outside of the battery pack along a discharge
path extending in the direction (direction Z1) in which the battery
cells B are arranged. In the discharge path, the gas discharged
from one of the battery cells B flows across other battery cells B
arranged in the direction (direction Z1), and thus thermal runaway
may occur at the other battery cells B.
[0092] Gas discharged from the cell vent V of a battery cell B may
be guided to the top cover TC along guide ribs GR surrounding the
cell vent V of the battery cell B. The top cover TC may have
protruding barrier walls PW which protrude toward the cell vents V
of the battery cells B. For example, the protruding barrier walls
PW may protrude toward the cell vents V from a main body of the top
cover TC.
[0093] The protruding barrier walls PW may protrude from the main
body of the top cover TC toward the frames F while vertically
extending in parallel with each other to have a substantially
uniform width in the protruding direction. The protruding barrier
walls PW may be fluidly connected to the guide ribs GR of the
frames F such that discharge paths may be provided as tunnel-type
discharge paths. The guide ribs GR has the oblique angle .theta. to
converge inward toward the centers of the cell vents V, and the
protruding barrier walls PW may have relatively wide cross-sections
for fluid connection with the guide ribs GR without leakage. The
protruding barrier walls PW may vertically extend in parallel with
each other such that the protruding barrier walls PW may have a
relatively wide uniform width.
[0094] The protruding barrier walls PW may be formed to surround
the cell vents V. Here, since the top cover TC is above the battery
cells B, it may be understood that the protruding barrier walls PW
surround upper sides of the cell vents V of the battery cells B
rather than the protruding barrier walls PW directly surrounding
the cell vents V of the battery cell B.
[0095] The protruding barrier walls PW may be formed to surround
the guide ribs GR. As described above, the protruding barrier walls
PW may has a relatively wide width for fluid connection with the
guide ribs GR without leakage such that the protruding barrier
walls PW having a relatively wide width may surround the outer
sides of the guide ribs GR.
[0096] The protruding barrier walls PW protruding from the main
body of the top cover TC toward the cell vents V are fluidly
connected to the guide ribs GR protruding from the main bodies of
the frames F in a direction opposite to the cell vents V. That is,
the protruding barrier walls PW and the guide ribs GR which
protrude in mutually-facing directions may be fluidly connected to
each other to provide the discharge paths as tunnel-type discharge
paths. High-temperature gas discharged from the cell vent V of a
battery cell B is guided toward a module vent MV of the top cover
TC via guide ribs GR and a protruding barrier wall PW provided
above the cell vent V without leakage between the top cover TC and
the frames F to adjacent battery cells B.
[0097] The guide ribs GR and the protruding barrier walls PW
protrude to face each other to form the discharge paths between the
top cover TC and the frames F, and owing to the combination of the
guide ribs GR and the protruding barrier walls PW, gas discharged
through the cell vents V may vertically flow through the discharge
paths without leakage. When gas discharged from the cell vent V of
any one of the battery cells B leaks from the discharge path
defined by the guide ribs GR and the protruding barrier wall PW to
an adjacent space between the top cover TC and the frames F,
adjacent battery cells B or circuit devices (not shown) of the
wiring board C may thermally deteriorate.
[0098] The guide ribs GR and the protruding barrier walls PW
protrude in mutually-facing directions from the frames F and the
top cover TC at positions corresponding to the cell vents V of the
battery cells such that the tunnel-type discharge paths fluidly
connected to the cell vents V may be formed between the top cover
TC and the frames F. The guide ribs GR and the protruding barrier
walls PW are formed to surround the cell vents V such that gas
discharged from the cell vent V of a battery cell B may not leak
from the tunnel-type discharge paths surrounded by the guide ribs
GR and the protruding barrier walls PW and may be rapidly
discharged to the outside of the battery pack through the
tunnel-type discharge path providing the shortest path without
having a negative effect on the circuit devices (not shown) of the
wiring board C or other battery cells B adjacent to the cell vent V
of the battery cell B.
[0099] As described above, although the guide ribs GR and the
protruding barrier walls PW provide, in combination, the
tunnel-type discharge paths, the guide ribs GR may not be in
contact with the protruding barrier walls PW but may be spaced
apart from the protruding barrier walls PW by clearance gaps (g).
The guide ribs GR formed on the frames F may entirely surround the
cell vents V as the frames F arranged forward and backward with the
battery cells B therebetween in the direction (direction Z1) are
coupled to each other. In this case, the frames F arranged forward
and backward and coupled to each other in the direction
(hereinafter, also referred to as the direction Z1) may be moved
away from each other in the direction (direction Z1) when the
battery cells B swell. In this case, when a battery cell B swells,
a pair of guide ribs GR coupled to each other to entirely surround
the cell vent V of the battery cell B may be moved outward away
from each other, and thus the pair of guide ribs GR may be away
from the protruding barrier wall PW. The swelling of each of the
battery cells B causes a pair of frames F coupled together with the
battery cell B therebetween to move away from each other (outward
directions) but does not affect the top cover TC arranged above the
battery cells B, such that the positions of the protruding barrier
walls PW formed on the top cover TC may not be varied and the
positions of the guide ribs GR formed on the frames F may be
varied. For this reason, the guide ribs GR are formed at inner
positions relatively close to the centers of the cell vents V, and
the protruding barrier walls PW are formed at outer positions
relatively distant from the centers of the cell vents V with
predetermined clearance gaps (g) between the protruding barrier
walls PW and the guide ribs GR such that the guide ribs GR may not
be moved outside the protruding barrier walls PW when each pair of
guide ribs GR connected to each other to entirely surround a cell
vent V are moved outward away from each other. That is, based on
the centers of the cell vents V, the guide ribs GR are formed at
inner positions relatively close to the centers of the cell vents
V, the protruding barrier walls PW are formed at outer positions
relatively distant from the centers of the cell vents V, and
predetermined gaps (g) are formed between the guide ribs GR formed
at the inner positions and the protruding barrier walls PW formed
at the outer positions such that the guide ribs GR may not be moved
outside the protruding barrier walls PW even when the guide ribs GR
are moved outward because of the swelling of the battery cells B.
Here, in the expression "the guide ribs GR are arrange at inner
positions and the protruding barrier walls PW are arranged at outer
positions," the inner positions and the outer positions may refer
to the positions of leading ends GRA and PWA of the guide ribs GR
and the protruding barrier walls PW which face each other. When the
guide ribs GR and the protruding barrier walls PW provide the
tunnel-type discharge paths, mutually-facing portions of the guide
ribs GR and the protruding barrier walls PW, that is, the leading
ends GRA of the guide ribs GR and the leading ends of the
protruding barrier walls PW at which the guide ribs GR and the
protruding barrier walls PW are fluidly connected to each other,
may mismatch each other and thus gas may leak between the guide
ribs GR and the protruding barrier walls PW. That is, the leading
ends GRA of the guide ribs GR in the protruding direction of the
guide ribs GR and the leading ends PWA of the protruding barrier
walls PW in the protruding direction of the protruding barrier
walls PW may be spaced apart from each other with the predetermined
clearance gaps (g) therebetween, and the leading ends GRA of the
guide ribs GR may be inside the leading ends PWA of the protruding
barrier walls PW.
[0100] In this way, the predetermined clearance gaps (g) are formed
between the guide ribs GR and the protruding barrier walls PW,
which arranged at inner positions and outer positions based on the
centers of the cell vents V. Although the clearance gaps (g) are
provided between the guide ribs GR and the protruding barrier walls
PW, gas discharged through the cell vents V may not leak through
the clearance gaps (g) while flowing along the tunnel-type
discharge paths. Since the guide ribs GR have the oblique angle
.theta. and converge inward toward the centers of the cell vents V,
gas discharged from the cell vents V may be concentrated toward the
centers of the cell vents V while being guided by the guide ribs
GR, and thus the gas discharged from the cell vents V may not leak
from the tunnel-type paths to a neighboring space through the
clearance gaps (g) formed outside the guide ribs GR.
[0101] Preferably, the clearance gaps (g) may designed such that
even when the guide ribs GR are moved outward in response to the
swelling of the battery cells B, the guide ribs GR may not be moved
outside the protruding barrier walls PW. More specifically, the
clearance gaps (g) may be designed by considering the swelling of
the battery cells B such that even when a pair of guide ribs GR
connected to each other to entirely surround a cell vent V are
maximally moved outward, the guide ribs GR may not be moved outside
the protruding barrier wall PW, for example, the leading ends GRA
of the guide ribs GR and the leading end PWA of the protruding
barrier wall PW may just face each other at the same positions. In
this case, each pair of guide ribs GR connected to each other at
front and rear positions with a battery cell B therebetween may be
moved away from each other in response to the swelling of the
battery cell B by a distance corresponding to the degree of
swelling of the battery cell B, and thus the clearance gaps (g) may
be set to correspond to the maximal degree of swelling of the
battery cells B.
[0102] As described above, the guide ribs GR and the protruding
barrier walls PW may be formed to be spaced apart from each other
with the predetermined clearance gaps (g) therebetween. In this
case, the guide ribs GR and the protruding barrier walls PW may be
respectively formed at inner positions relatively close to the
center positions of the cell vents V and outer positions relatively
distant from the center positions of the cell vents V with the
predetermined clearance gaps (g) being between the guide ribs GR
and the protruding barrier walls PW. In addition, the guide ribs GR
and the protruding barrier walls PW may be spaced apart from each
other in a vertical direction. The guide ribs GR and the protruding
barrier walls PW may be spaced apart from each other by a
predetermined clearance by considering assembly tolerance among the
frames F on which the guide ribs GR are formed, the top cover TC on
which the protruding barrier walls PW are formed, and the wiring
board C between the frames F and the top cover TC.
[0103] The guide ribs GR and the protruding barrier walls PW may
protrude in mutually-facing directions from the main bodies of the
frames F (or the support portions FS of the frames F) and the main
body of the top cover TC, and may form, in combination, the
tunnel-type discharge paths between the main bodies of the frames F
(or the support portions FS of the frames F) and the main body of
the top cover TC.
[0104] FIG. 6 is another exploded perspective view illustrating the
battery pack shown in FIG. 1.
[0105] Referring to the drawing, the wiring board C may be arranged
between the frames F and the top cover TC. The wiring board C
collects state information of the battery cells B such as the
voltages or temperatures of the battery cells B, and transmits the
state information to a separate battery management unit (not shown)
or controls the charge-discharge operations of the battery cells B
based on the collected state information. To this end, a plurality
of circuit devices (not shown) may be mounted on upper and lower
surfaces of the wiring board C.
[0106] Through-holes CV may be formed in the wiring board C so as
not to obstruct the tunnel-type discharge paths provided by the
guide ribs GR and the protruding barrier walls PW. More
specifically, the protruding barrier walls PW or the guide rib GR
may extend and be assembled through the through-holes CV of the
wiring board C, and the tunnel-type discharge paths provided by the
guide ribs GR and the protruding barrier walls PW may penetrate the
wiring board C through the through-holes CV. For example, the
protrusion barrier walls PW may protrude from the main body of the
top cover TC and may penetrate the wiring board C as being fitted
into the through-holes CV. In another embodiment of the present
disclosure, the guide ribs GR may protrude from the main bodies of
the frames F (or the support portions FS of the frames F) and may
penetrate the wiring board C as being fitted into the through-holes
CV. As described above, the tunnel-type discharge paths provided by
the guide ribs GR and the protruding barrier walls PW which
protrude to face each other may extend through the through-holes CV
of the wiring board C without being obstructed, and thus gas
discharged from the cell vents V may not permeate into the wiring
board C, thereby fundamentally preventing deterioration of the
circuit elements (not shown) mounted on the wiring board C. For
example, since the protruding barrier walls PW or the guide ribs GR
penetrate the wiring board C as being inserted into the
through-holes CV, the tunnel-type discharge paths provided by the
protruding barrier walls PW and the guide ribs GR may not be open
to the wiring board C or the circuit elements (not shown) of the
wiring board C.
[0107] Preferably, the protruding barrier walls PW or the guide
ribs GR may be inserted through the through-holes CV of the wiring
board C such that the protruding barrier walls PW or the guide ribs
GR may completely penetrate the wiring board C. Since there is a
risk of gas leakage at the leading ends PWA and GRA (refer to FIG.
5) at which the protruding barrier walls PW and the guide rib GR
are connected to each other, when the protruding barrier walls PW
and the guide ribs GR are connected to each other inside the
through-holes CV, that is, when the leading ends PWA (refer to FIG.
5) of the protruding barrier walls PW and the leading ends GRA
(refer to FIG. 5) of the guide ribs GR are located to face each
other inside the through-holes CV, the wiring board C and the
circuit elements (not shown) of the wiring board C may deteriorate
due to gas leakage.
[0108] The module vents MV may be formed on the top cover TC. The
module vents MV may be formed at positions corresponding to the
cell vents V of the battery cells B. More specifically, the module
vents MV may be formed at positions corresponding to the protrusion
barrier walls PW of the top cover TC. Since the protrusion barrier
walls PW of the top cover TC provides the discharge paths, gas
flowing through the discharge paths may be guided to the module
vents MV by the protrusion barrier walls PW.
[0109] FIG. 7 is a view illustrating a module vent shown in FIG. 6.
FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG.
7.
[0110] Referring to the drawings, each of the module vents MV may
be formed by a break line BL which is formed by recessing a portion
of the top cover TC corresponding to a cell vent V to a
predetermined depth. The module vent MV may be formed by a break
line BL engraved to a predetermined depth without using an
additional member such as tape, and a groove may be formed in the
upper or lower surface of the top cover TC by recessing a portion
of the upper or lower surface of the top cover TC in the depth
direction thereof to form the break line BL. Since the module vent
MV is formed by the break line BL which is a groove having a
predetermined depth in the top cover TC, an additional assembly
process for attaching an additional member such as tape to the top
cover TC is not necessary.
[0111] Each module vent MV may be formed in a closed loop
surrounding the cell vent V of a battery cell B. For example, the
break line BL forming the module vent MV may include a border line
PL formed in a closed loop to define the module vent MV, and a
center line CL crossing the border line PL.
[0112] The center line CL may be formed at a center position of the
module vent MV in a direction crossing the module vent MV. The
center line CL may be rapidly broken by the pressure of gas which
is concentrated at the center position under the guidance of the
guide ribs GR inclined to converge toward the center position.
[0113] For example, hinge portions H may be formed on portions of
the border line PL such that the module vent MV may be opened at
both sides of the center line CL. The hinge portions H may be
formed on both lateral portions of the border line PL which face
the center line CL, and the hinge portions H may have a relatively
thick thickness such that when the module vent MV is broken, the
module vent MV may not be separated from the top cover TC but may
maintain connection with the top cover TC through the hinge
portions H. When the module vent MV is operated in response to the
pressure of gas discharged from the cell vent V, the module vent MV
is broken along the center line CL into two parts while maintaining
connection with the top cover TC through the hinge portions H
facing the center line CL without being separated and scattered
from the top cover TC. When the module vent MV is separated and
scattered outward from the top cover TC as a result of breakage of
the module vent MV, the module vent MV may collide with an external
structure. Thus, the module vent MV is designed such that when the
module vent MV is broken, the module vent MV may not be completely
separated from the top cover TC owing to the hinge portions H
without hindering the breakage of the module vent MV.
[0114] That is, as the center line CL is broken, the module vent MV
may be opened toward both sides of the center line CL as being
folded at the hinge portions H while maintaining connection with
the top cover TC through the hinge portions H.
[0115] Both ends of the center line CL may be in contact with the
border line PL, and intersection points BO between the center line
CL and the border line PL may be break start points. That is, the
intersection points BO formed at both ends of the center line CL
may correspond to break start points, and break starting from both
ends of the center line CL may propagate to the entirety of the
break line BL except for the hinge portions H while propagating
along the center line CL and the border line PL on both sides of
the center line CL, thereby completely opening the module vent MV.
That is, when the module vent MV is broken, the hinge portions H
may remain in connection with the top cover TC without being
broken.
[0116] Referring to FIG. 8, the thickness t1 of the hinge portions
H may preferably be greater than the thickness t2 of the center
line CL. Owing to this, when the module vent MV is broken starting
from the center line CL, the hinge portions H may remain in
connection with the top cover TC without being broken.
[0117] More specifically, it may be designed that the thickness t1
of the hinge portions H is 70% or less of the thickness t0 of the
top cover TC. When the thickness t1 of the hinge portions H is
greater than 70% of the thickness t0 of the top cover TC, the hinge
portions H may not be easily folded, and thus the module vent MV
may not be easily opened.
[0118] It may be designed that the thickness of the break line BL
such as the thickness t2 of the center line CL other than the
thickness t1 of the hinge portions H is 30% or less of the
thickness t0 of the top cover TC. When the thickness t2 of the
center line CL is greater than 30% of the thickness t0 of the top
cover TC, it may be difficult to start breaking at the center line
CL. The thickness of the break line BL may be varied depending on a
set operating pressure of the module vent MV, and may be designed
to facilitate the folding operation of the hinge portions H and the
break of the center line CL.
[0119] In the present disclosure, the guide ribs GR may be designed
to concentrate the pressure of gas discharged from the cell vent V
on the center position of the module vent MV, and the break line BL
of the module vent MV may be designed to start breakage at the
center position of the module vent MV, thereby guaranteeing rapid
breakage of the module vent MV. When the breakage of the module
vent MV does not occur rapidly but occurs slowly in a dangerous
situation such as overheating, gas discharged from the cell vent V
may not be discharged to the outside but may be trapped inside the
top cover TC, and thus other battery cells B or circuit devices may
deteriorate.
[0120] The module vents MV may be provided such that the module
vents MV may respectively correspond to the cell vents V of the
battery cells B. That is, the module vents MV may be formed on the
top cover TC extending across the battery cells B at positions
respectively corresponding to the cell vents V of the battery cells
B, and gas discharged from the cell vents V may be discharged to
the outside of the battery pack through the module vents MV
respectively corresponding to the cell vents V instead of being
discharged to the outside of the battery pack through a discharge
path crossing the battery cells B to collect gas discharged from
the cell vents V or a single vent formed at a particular position
of the top cover TC. Owing to this structure, when some of the
battery cells B are locally overheated, high-temperature,
high-pressure gas discharged from the cell vents V of the
overheated battery cells B may be rapidly discharged through the
shortest paths in a vertical direction without deteriorating other
battery cells B while crossing the other battery cells B.
[0121] FIG. 9 is a view illustrating a modification of the guide
ribs GR shown in FIG. 5, according to another embodiment.
[0122] Referring to the drawing, guide ribs GR' and the protruding
barrier wall PW protrude in mutually-facing directions from the
main bodies of the frames F (or the support portions FS of the
frames F) and the main body of the top cover TC. The guide ribs GR'
are formed at inner positions relatively close to the center of the
cell vent V, and the protruding barrier wall PW are formed at an
outer position relatively distant from the center of the cell vent
V. In addition, a clearance gap (g) may be formed between leading
ends GRA of the guide ribs GR' and the leading end PWA of the
protruding barrier wall PW as a measure for the swelling of the
battery cell B.
[0123] In the present embodiment, the guide ribs GR' may include:
inclined portions GR1 formed in a shape converging toward the
center of the cell vent V; and extension portions GR2 bent from the
inclined portions GR1 and extending in parallel with the protruding
barrier wall PW. The inclined portions GR1 may have a
cross-sectional shape gradually decreasing in an upward direction
of a discharge path, and the extension portions GR2 may have a
uniform cross-sectional shape and may extend in parallel with each
other in the upward direction of the discharge path. That is, the
extension portions GR2 may extend in a uniform cross-sectional
shape corresponding to the minimum cross-section of the inclined
portions GR1 and may form the leading ends GRA of the guide ribs
GR'. The extension portions GR2 may be fluidly connected to the
protruding barrier wall PW.
[0124] The present disclosure has been described with reference to
the embodiments shown in the accompanying drawings for illustrative
purposes only, and it will be understood by those of ordinary skill
in the art that various modifications and equivalent other
embodiments may be made therefrom. Therefore, the scope and spirit
of the present disclosure should be defined by the following
claims.
INDUSTRIAL APPLICABILITY
[0125] The present disclosure may be applied to battery packs which
are rechargeable energy sources, and to various devices using
battery packs as power sources.
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